tubular part, the small intestine (SD?t), and of a great terminal receptacle, the rectum (Rert), filled with a mass of soft orange-colored matter. In the fully-matured insect (C), after it has escaped from the cocoon, still fu,'ther
C? ? 8Int
FiG. I64. Transformation in the form of the alimentary canal of the tent caterpillar from the larva to the adult moth A, alimentary canal of the caterpillar. B, the same of the pupa. C, the same of the moth Cr, crop; Int, intestine; Mal, Malpighian tubules (hOt shown full length); Oe, oesophagus; Rect, rectum; Slnt, small intestine; l?ent, centriculus
alterations have taken place. The crop sac (Cr) is now greatly distended into a spherical vesicle tensely filled wlth gas--air, probably, that the moth has swallowed, perhaps to aid it in breaking the pupal shell, for there are sometlmes small bubbles also in the tubular oesophagus.
[31o]
THE
